Cell used
Normally, 18650 lithium-ion batteries are used, and square or lithium polymer batteries are used for thin designs.
The capacity of 18650 cells has been increasing, and the current cutting edge is 3600mAh.
Charging current and maximum discharging current are not necessarily increasing in proportion to the increase in capacity, but it seems that as the capacity increases the charging timeand the maximum discharging current seem to be kept at the same value as the conventional product.